Specialized organ donor programs have been implemented in the U.S. and other countries with varying degrees of success. Perhaps the most important concern of any organ donor program is the availability of organs. At the next level, however, there is an equally important concern that the donor organ tissue be suitable for the intended use. Specifically, it is necessary for the donor tissue to be suitable for transplant surgery.
In the particular case where the donor tissue is tissue from the cornea of a donor eye, the question of suitability for purposes of transplant surgery is actually two-fold. First, it is necessary for the healthcare professional to assess information about the donor tissue which will assure there is a suitable match between the donor and the recipient. Here, the obvious reason for having a good match is that there will be a more effective surgical outcome with consequent better patient response and recovery. Second, it is also necessary for the healthcare professional to know the precise dimensions and shape (refractive properties) of the eye. Such knowledge not only allows better control of the tissue interface between the donor tissue and the recipient during surgery, it also leads to a better post-surgical visual outcome. Specifically, insofar as the post-surgical visual outcome is concerned, it is important that the necessary refractive corrections provided by the donor corneal tissue be precisely controlled relative to the pre-surgical condition of the recipient.
When assessing corneal tissue for its suitability for transplant surgery, several considerations must be taken. For one, it is important to assess and evaluate the health of the donor tissue. This can be done by evaluating the extent, if any, to which the cornea may have been earlier affected by corneal scarring or corneal disease. It is well known that such an evaluation can be done using optical techniques. Additionally, as another consideration, it is important to assess the material properties of the donor tissue. Specifically, material properties of a cornea such as density, amorphousness, crystallinity, and transparency can affect the suitability of the corneal tissue as a candidate for transplant surgery. It is also well known that such an evaluation can be accomplished using optical interference techniques.
The present invention recognizes that the surgical suitability concerns mentioned above with regard to corneal tissue can be addressed if the donor tissue is appropriately accessible. Appropriate accessibility, however, requires that the donor corneal tissue be properly preserved and that it not be unduly disturbed during evaluation. Further, due to the fact that many material properties involve optical measurements and evaluations of the cornea, accessibility also requires that the donor corneal tissue be appropriately positioned for illumination by light beams and for evaluation by optical detectors.
In light of the above, it is an object of the present invention to provide a sample cell which can be used to image a tissue sample for purposes of screening the sample to identify compromised donor corneal tissue. Another object of the present invention is to provide a sample cell for use in imaging a tissue sample which is adaptable for imaging the sample using both transmitted light and scattered light. Still another object of the present invention is to provide a sample cell for use in imaging a tissue sample which is allows the tissue sample to be measured both for its physical dimensions as well as for its material properties. Yet another object of the present invention is to provide a sample cell for use in imaging a tissue sample which is easy to use, relatively simple to manufacture, and comparatively cost effective.